Some driver circuit applications are designed to provide a driving current, such as for groups of light-emitting diodes (LEDs). The number of LEDs may vary depending on the specific application. A driver may control the current flowing through the LED chain, while the output voltage may be set by the number and the forward voltage of the LEDs that compose the chain. In many applications, it is desirable for the driver to deliver a constant average current (as opposed to, e.g., a constant voltage) through the load when the load is switched on. The driver may be incorporated in a larger system that may have mixed or ambiguous power requirements, particularly when the system is designed in typical engineering compromise among competing design constraints including low cost, fast response, and small sized components. For example, some systems provide power to a driver converted from AC to DC, although competing design constraints sometimes dictate that this conversion is done imperfectly, such as using a rectifier and a relatively undersized smoothing capacitor.